Oral care composition with cross-linked polymer peroxide

ABSTRACT

Oral care compositions comprising:
         (a) a peroxide complex comprising a peroxide component and an N-vinyl heterocyclic polymer (e.g., poly-N-vinyl polylactam, or poly-N-vinyl-polyimide);   (b) a whitening agent (e.g., hydrogen peroxide); and   (c) an orally acceptable carrier.
 
In one embodiment, the carrier comprises a film forming material. Methods are also provided for making an oral care composition comprising:
   (a) mixing a whitening agent, silicone adhesive and carrier fluid to form a homogenous mixture;   (b) adding a peroxide complex to said homogenous mixture, wherein said complex comprises hydrogen peroxide and an N-vinyl heterocyclic polymer; and   (c) mixing under vacuum.

INTRODUCTION

The present invention relates to oral care compositions and methods. Inparticular, the present invention includes compositions and methods forwhitening of teeth.

Many individuals desire a “bright” smile and white teeth, and considerdull and stained teeth cosmetically unattractive. Unfortunately, withoutpreventive or remedial measures, stained teeth are almost inevitable dueto the absorbent nature of dental material. Everyday activities such assmoking or other oral use of tobacco products, and eating, chewing ordrinking certain foods and beverages (in particular coffee, tea and redwine), cause undesirable staining of surfaces of teeth. Staining canalso result from microbial activity, including that associated withdental plaque. The chromogens or color causing substances in thesematerials become part of the pellicle layer and can permeate the enamellayer. Even with regular brushing and flossing, years of chromogenaccumulation can impart noticeable tooth discoloration.

A tooth is comprised of an inner dentin layer and an outer hard enamellayer that is the protective layer of the tooth. The enamel layer of atooth is naturally opaque, and white or a slightly off-white color. Theenamel layer is composed of hydroxyapatite mineral crystals that createa somewhat porous surface. These hydroxyapatite crystals formmicroscopic hexagonal rods or prisms that make up the enamel surface. Asa result, the surface of the enamel presents microscopic spaces or poresbetween the prisms. Without limiting the mechanism, function or utilityof present invention, it is believed that this porous nature of theenamel is where discoloring substances permeate the enamel and discolorthe teeth.

There are a variety of compositions described in the art for preventingor treating the discoloration of teeth. In particular, to combatstaining and brighten or restore the natural enamel color, a variety ofproducts containing bleaching materials are commercially available forprofessional and consumer use. The most commonly accepted chemicals usedin teeth whitening today are peroxides. Peroxides are generally deemedsafe from a physiological standpoint, and can be effective to whitenteeth. Such peroxides include hydrogen peroxide, carbamide peroxide,sodium perborate, and sodium percarbonate. When these peroxides are inappropriate contact with teeth they will usually oxidize stains,rendering the teeth whiter.

Professional dental treatments frequently include a tooth surfacepreparation such as acid etching followed by the application of highlyconcentrated bleaching solutions (e.g., up to 37% hydrogen peroxide)and/or the application of heat or light. (See, e.g., U.S. Pat. Nos.5,425,953 and 5,766,574.) These procedures provide rapid results, butare expensive, and often require several trips to the dentist. In manycases, the patient's lips are uncomfortably retracted during the entiretreatment and the patient is confined to sitting in the dental chair.

Alternatively, at home bleaching systems can be used. These systems havegained significant popularity in the past decade because of reducedcost, and increased convenience. Instead of time consuming and frequenttrips to the dentist, the tooth whitener is purchased at a consumerretail store and may be used while performing other personal tasks orerrands, relaxing or sleeping.

Current home treatment methods include abrasive toothpastes, toothpastesthat produce oxides, whitening gels for use with a dental tray andwhitening strips. The effectiveness of such techniques depends on avariety of factors including the type and intensity of the stain, thetype of bleaching agent, contact time of the bleaching agent on theteeth, the amount of available bleaching active in the composition, theability of the bleaching agent to penetrate the tooth enamel, andconsumer compliance. Effectiveness is also dependant on the amount ofbleaching active in the composition, the ability of the active to bereleased during use, and the stability of the active in the product.However, the effectiveness of many of these treatments is adverselyaffected because of deficiencies in one or more factors relating to thecomposition and consumer compliance.

SUMMARY

The present invention provides oral care compositions. Embodimentsinclude oral care compositions comprising:

-   -   (a) a peroxide complex comprising a peroxide component and an        N-vinyl heterocyclic polymer;    -   (b) a whitening agent; and    -   (c) an orally acceptable carrier.        In various embodiments, the N-vinyl heterocyclic polymer        comprises a polymer selected from the group consisting of        poly-N-vinyl polylactams, poly-N-vinyl-polyimides and mixtures        thereof. In one embodiment, the carrier comprises a film forming        material. In one embodiment, the carrier comprises a silicone        adhesive. In one embodiment, the whitening agent is a peroxide        compound.

Methods are also provided for making an oral care compositioncomprising:

-   -   (a) mixing a whitening agent, silicone adhesive and carrier        fluid to form a homogenous mixture;    -   (b) adding a peroxide complex to said homogenous mixture,        wherein said complex comprises hydrogen peroxide and an N-vinyl        heterocyclic polymer; and    -   (c) mixing under vacuum.        Methods are also provided for whitening a tooth surface,        comprising applying a composition comprising a safe and        effective amount of a peroxide complex and a whitening agent.

It has been discovered that compositions and methods of this inventionafford advantages over oral care compositions among known in the art,including one or more of enhanced whitening efficacy, providing a higheravailable concentration of bleaching agent, tooth adherence in thepresence of saliva without the use of a dental tray, and release of thebleaching agent over a period of time. Further uses, benefits andembodiments of the present invention are apparent from the descriptionset forth herein.

DESCRIPTION

The following definitions and non-limiting guidelines must be consideredin reviewing the description of this invention set forth herein. Theheadings (such as “Introduction” and “Summary,”) and sub-headings (suchas “Compositions” and “Methods”) used herein are intended only forgeneral organization of topics within the disclosure of the invention,and are not intended to limit the disclosure of the invention or anyaspect thereof. In particular, subject matter disclosed in the“Introduction” may include aspects of technology within the scope of theinvention, and may not constitute a recitation of prior art. Subjectmatter disclosed in the “Summary” is not an exhaustive or completedisclosure of the entire scope of the invention or any embodimentsthereof. Classification or discussion of a material within a section ofthis specification as having a particular utility (e.g., as being an“active” or a “carrier” ingredient) is made for convenience, and noinference should be drawn that the material must necessarily or solelyfunction in accordance with its classification herein when it is used inany given composition.

The citation of references herein does not constitute an admission thatthose references are prior art or have any relevance to thepatentability of the invention disclosed herein. Any discussion of thecontent of references cited in the Introduction is intended merely toprovide a general summary of assertions made by the authors of thereferences, and does not constitute an admission as to the accuracy ofthe content of such references. All references cited in the Descriptionsection of this specification are hereby incorporated by reference intheir entirety.

The description and specific examples, while indicating embodiments ofthe invention, are intended for purposes of illustration only and arenot intended to limit the scope of the invention. Moreover, recitationof multiple embodiments having stated features is not intended toexclude other embodiments having additional features, or otherembodiments incorporating different combinations the stated of features.Specific Examples are provided for illustrative purposes of how to makeand use the compositions and methods of this invention and, unlessexplicitly stated otherwise, are not intended to be a representationthat given embodiments of this invention have, or have not, been made ortested.

As used herein, the words “preferred” and “preferably” refer toembodiments of the invention that afford certain benefits, under certaincircumstances. However, other embodiments may also be preferred, underthe same or other circumstances. Furthermore, the recitation of one ormore preferred embodiments does not imply that other embodiments are notuseful, and is not intended to exclude other embodiments from the scopeof the invention.

As used herein, the word ‘include,” and its variants, is intended to benon-limiting, such that recitation of items in a list is not to theexclusion of other like items that may also be useful in the materials,compositions, devices, and methods of this invention.

As referred to herein, all compositional percentages are by weight ofthe total composition, unless otherwise specified.

Compositions

The present invention provides oral care compositions and methods foradministration or application to, or use with, a human or other animalsubject. As referred to herein, an “oral care composition” is anycomposition that is suitable for administration or application to theoral cavity a human or animal subject for enhancing the health, hygieneor appearance of the subject, preferably providing such benefits as: theprevention or treatment of a condition or disorder of the teeth, gums,mucosa or other hard or soft tissue of the oral cavity; the preventionor treatment of a systemic condition or disorder; the provision ofsensory, decorative or cosmetic benefits; and combinations thereof. Invarious preferred embodiments, an oral care composition is notintentionally swallowed, but is rather retained in the oral cavity for atime sufficient to effect the intended utility. Preferably, specificmaterials and compositions to be used in this invention are,accordingly, pharmaceutically- or cosmetically-acceptable. As usedherein, such a “pharmaceutically acceptable” or “cosmeticallyacceptable” component is one that is suitable for use with humans and/oranimals to provide the desired therapeutic, prophylactic, sensory,decorative, or cosmetic benefit without undue adverse side effects (suchas toxicity, irritation, and allergic response) commensurate with areasonable benefit/risk ratio.

Peroxide Complex:

The present invention provides compositions comprising a peroxidecomplex. The peroxide complex is preferably present at a level of fromabout 0.5% to about 40%, optionally from about 20% to about 30%. In apreferred embodiment, the concentration of the peroxide complex is suchthat the peroxide component of the peroxide complex is present at alevel of about 10% of the total composition weight, optionally fromabout 1% to about 6% of the total composition weight.

The peroxide complex comprises a peroxide component and a porouscross-linked polymer. As referred to herein, a “peroxide component” isany oxidizing compound comprising a bivalent oxygen-oxygen group.Peroxide components include peroxides and hydroperoxides, such ashydrogen peroxide, peroxides of alkali and alkaline earth metals,organic peroxy compounds, peroxy acids, pharmaceutically-acceptablesalts thereof, and mixtures thereof. Peroxides of alkali and alkalineearth metals include lithium peroxide, potassium peroxide, sodiumperoxide, magnesium peroxide, calcium peroxide, barium peroxide, andmixtures thereof. Organic peroxy compounds include carbamide peroxide(also known as urea hydrogen peroxide), glyceryl hydrogen peroxide,alkyl hydrogen peroxides, dialkyl peroxides, alkyl peroxy acids, peroxyesters, diacyl peroxides, benzoyl peroxide, and monoperoxyphthalate, andmixtures thereof. Peroxy acids and their salts include organic peroxyacids such as alkyl peroxy acids, and monoperoxyphthalate and mixturesthereof, as well as inorganic peroxy acid salts such as percarbonate andperborate salts of alkali and alkaline earth metals such as lithium,potassium, sodium, magnesium, calcium and barium, and mixtures thereof.In various embodiments, the peroxide component comprises hydrogenperoxide, urea peroxide, sodium percarbonate and mixtures thereof. Inone embodiment, the peroxide component comprises hydrogen peroxide. Inone embodiment, the peroxide component consists essentially of hydrogenperoxide.

The peroxide complex also comprises an N-vinyl heterocyclic polymer.Preferably, the polymer is crosslinked and adsorbs, absorbs, complexes,or otherwise retains the peroxide component. The chemical and physicalcharacteristics of the particulate hinder the release of the peroxidecompound from the polymer particulates, and in some embodiments providescontrolled release of the peroxide compound. The peroxide complexpreferably comprises a peroxide component at a level of from about 0.1%to about 25%, optionally from about 1% to about 25%, optionally fromabout 5% to about 18% by weight of the peroxide composite. In oneembodiment, the composition comprises commercially available complex ofperoxide adsorbed to cross-linked polyvinylpyrrollidone. Such productsinclude, for example, Peroxydone XL-10 and Peroxydone K-30, marketed byISP Corporation, Wayne, N.J., USA.

The N-vinyl heterocyclic polymer is derived from a N-heterocyclic vinylmonomer, preferably comprising N-vinyl heterocyclic monomers having from3 to 7 atoms in a heterocyclic ring, including a carbonyl carbon atomand a nitrogen heteroatom containing a vinyl group. Preferably the ringcontains 5 or 6 atoms, comprises heteroatoms such as sulfur or oxygen,and may be substituted or unsubstituted.

Certain embodiments are the polymers of specific N-vinyl heterocyclicmonomers such as N-vinyl imides to form poly-N-vinyl polyimides, andN-vinyl lactams to form poly-N-vinyl polylactams, and mixtures thereof.Suitable N-vinyl imides include: N-vinyl malonimide; N-vinylsuccinimide; N-vinyl glutarimide; N-vinyl maleimide; N-vinylβ-methylglutarimide; N-vinyl α-amylsuccinimide; and N-vinyl adipimide.

Suitable N-vinyl lactams include: N-vinyl peperidone; N-vinylcaprolactam; N-vinyl-3-methyl pyrrolidinone or piperidone, orcaprolactam; N-vinyl-4-methyl pyrrolidinone, or piperidone orcaprolactam; N-vinyl-5-methyl pyrrolidinone or piperidone;N-vinyl-3-ethyl pyrrolidinone; N-vinyl-4,5-dimethyl pyrrolidinone;N-vinyl-5,5-dimethyl pyrrolidinone; N-vinyl-3,3,5-trimethylpyrrolidinone; N-vinyl-5-methyl-5-ethyl pyrrolidinone;N-vinyl-3,4,5-trimethyl-3-ethyl pyrrolidinone;N-vinyl-6-methyl-2-piperidone; N-vinyl-6-ethyl-2-piperidone;N-vinyl-3,5-dimethyl-2-piperidone; N-vinyl-4,4-dimethyl-2-piperidone;N-vinyl-7-methyl caprolactam; N-vinyl-7-ethyl caprolactam;N-vinyl-3,5-dimethyl caprolactam; N-vinyl-4,6-dimethyl caprolactam;N-vinyl-3,5,7-trimethyl caprolactam.

Embodiments containing poly-N-vinyl polylactams, include but are notlimited to poly-N-vinyl pyrrolidone, poly-N-vinyl-2-piperidone,poly-N-vinyl-2-caprolactam, poly-N-vinyl-3-methyl-2-caprolacam,poly-N-vinyl-3-methyl-2-piperidone, poly-N-vinyl-4-methyl-2-piperidone,poly-N-vinyl-4-methyl-2-caprolactam, poly-N-vinyl-3-ethyl-2-pyrrolidone,poly-N-vinyl-4,5-dimethyl-2-pyrrolidone, and mixtures thereof.Preferably, the polymer is selected from the group consisting ofpoly-N-vinyl poly-2-pyrrolidone, poly-N-vinyl-poly-2-piperidone,poly-N-vinyl-poly-2-caprolactam and mixtures thereof.

In a preferred embodiment, the polymer ispoly-N-vinyl-poly-2-pyrrolidone. The poly-N-vinyl-poly-2-pyrrolidone isalso commonly known as polyvinylpyrrolidone or “PVP”. PVP refers to apolymer containing vinylpyrrolidone (also referred to asN-vinylpyrrolidone, N-vinyl-2-pyrrolidione and N-vinyl-2-pyrrolidinone)as a monomeric unit. The monomeric unit, consists of a polar imidegroup, four non-polar methylene groups and a non-polar methane group.The polymers include soluble and insoluble homopolymeric PVPs.Copolymers containing PVP include vinylpyrrolidone/vinyl acetate (alsoknown as Copolyvidone, Copolyvidonum or VP-VAc) and vinylpyrrolidone/dimethyl amino-ethylmethacrylate.

Soluble PVP polymers among those useful herein are known in the art,including Povidone, Polyvidone, Polyvidonum,poly(N-vinyl-2-pyrrolidinone), poly(N-vinylbutyrolactam),poly(l-vinyl-2-pyrrolidone) and poly[1-(2-oxo-1pyrrolidinyl)ethylene].These PVP polymers are not substantially cross-linked.

In various embodiments of this invention, an insoluble cross-linkedhomopolymer is preferred. Such polymers include those commonly referredto in the art as polyvinylpolypyrrolidone, cross-povidone, and cPVP, andare referred to herein as “cPVP.” The homopolymer is prepared by freeradical polymerization of the monomer vinylpyrollidone.

In one embodiment, the poly-N-vinyl-poly-2-pyrrolidone has a lactam ofthe pyrrolidone ring that provides the hydrophilic characteristics.Without limiting the composition, mechanism, or function the invention,it is believed that such groups allow the peroxide compound to bind tothe cPVP. The hydrophobic characteristics attributed to the methylenegroups in the ring and the linear aliphatic backbone prevent theperoxide complex from reacting with saliva while still maintaining theperoxide available to whiten the teeth. The surface characteristic ofthe cPVP serve as a barrier to the passage of the peroxide component andprevents the premature distribution of the peroxide component uponapplication of the oral care composition to the oral cavity. The cPVPlinked peroxide is released over a period of time through diffusion,temperature variance, moisture levels and other factors.

Polymer particulates useful herein may be made by well establishedprocesses. The poly-N-vinyl polylactams are produced by polymerizing avinyl lactam in the presence of an alkaline catalyst. (See, U.S. Pat.No. 2,938,017, Grosser, et al, issued May 24, 1960; U.S. Pat. No.3,277,066, Grosser, et al, issued Oct. 4, 1966, and U.S. Pat. No.3,306,886, Grosser, et al, issued Feb. 28, 1967). Embodiments containingpoly-N-vinyl polyimides are produced by heating an N-vinyl imide in thepresence of a catalyst. (See, U.S. Pat. No. 3,306,881, Grosser, et al,issued Feb. 28, 1967). In alternative embodiments comprising aco-polymer of the N-vinyl heterocyclic compound is produced bypolymerizing N-vinyl heterocyclic and dissimilar vinyl monomers. (SeeU.S. Pat. No. 2,667,473, Morner, et al, issued Jan. 26, 1954; and U.S.Pat. No. 2,947,633, Perry et al, issued Aug. 2, 1960).

Porous cross-linked polymers among those useful herein include thosecommercially available as: Kollidon® and Luvicross®, marketed by BASF,Mount Olive, N.J., USA; PVP K-Series or Povidone K-30 marketed by AAAInternational Corp., Downers Grove, Ill., USA; PVP K-30 USP24 andindustry grade, PVP VA-64, PVP K-17 and PVP K-90, marketed by Peakchem,Hangzhou, China; and PolyPlasdone® INF-10, marketed by ISP Corporation,Wayne, N.J., USA. It is understood that embodiments of the invention arenot limited to a PVP of a specific molecular weight and that anyequivalent PVP of acceptable purity, preferably pharmaceutical grade, iswithin the scope of embodiments of this invention.

In various embodiments, the peroxide complex is made by suspending thepolymer (preferably cPVP) in a suitable anhydrous organic solvent. Ananhydrous solution of the peroxide component is made, preferablyutilizing the same organic solvent as the PVP suspension. The peroxidesolution is combined with the PVP suspension in an amount correspondingto the desired molar ratio of polymer peroxide of the peroxide complex.(See, U.S. Pat. No. 5,108,742, Merianos, issued Apr. 28, 1992; and U.S.Pat. No. 4,564,514, Druaz, et al, issued Jan. 14, 1986.) In oneembodiment, the peroxide complex has an equal (1:1) molar ratio ofhydrogen peroxide to the polymer.

Whitening Agent

In various embodiments, the compositions of the present inventioncomprise a whitening agent. As further discussed below, a “whiteningagent” is a material which is effective to effect whitening of a toothsurface to which it is applied. In various embodiments, the compositionsof this invention comprise a peroxide whitening agent, comprising aperoxide compound. As referred to herein, a “peroxide compound” is anoxidizing compound comprising a bivalent oxygen-oxygen group. Peroxidecompounds include peroxides and hydroperoxides, such as hydrogenperoxide, peroxides of alkali and alkaline earth metals, organic peroxycompounds, peroxy acids, pharmaceutically-acceptable salts thereof, andmixtures thereof. Peroxides of alkali and alkaline earth metals includelithium peroxide, potassium peroxide, sodium peroxide, magnesiumperoxide, calcium peroxide, barium peroxide, and mixtures thereof.Organic peroxy compounds include carbamide peroxide (also known as ureahydrogen peroxide), glyceryl hydrogen peroxide, alkyl hydrogenperoxides, dialkyl peroxides, alkyl peroxy acids, peroxy esters, diacylperoxides, benzoyl peroxide, and monoperoxyphthalate, and mixturesthereof. Peroxy acids and their salts include organic peroxy acids suchas alkyl peroxy acids, and monoperoxyphthalate and mixtures thereof, aswell as inorganic peroxy acid salts such as persulfate, dipersulfate,percarbonate, perphosphate, perborate and persilicate salts of alkaliand alkaline earth metals such as lithium, potassium, sodium, magnesium,calcium and barium, and mixtures thereof. In various embodiments, theperoxide compound comprises hydrogen peroxide, urea peroxide, sodiumpercarbonate and mixtures thereof. In one embodiment, the peroxidecompound comprises hydrogen peroxide. In one embodiment, the peroxidecompound consists essentially of hydrogen peroxide. The peroxidecompound comprises from about 0.1% to about 50%, optionally from about1% to about 40%, optionally from about 10% to about 30% of the oral carecomposition.

The peroxide compound may be the same as or different than the peroxidecomponent. In one embodiment, the peroxide component and the peroxidecompound are the same, both comprising hydrogen peroxide. The peroxidecompound may be formulated in the composition as an aqueous solution. Inone embodiment, the composition comprises an aqueous solution ofhydrogen peroxide, comprising approximately 35% hydrogen peroxide inwater.

In one embodiment, the concentration of the peroxide complex is limitedso that the peroxide component is no more than 6%, so as to maintain anpreferred viscosity. In such an embodiment, the combination of theperoxide complex and peroxide compound comprise a total peroxideconcentration of greater than 6%, operable to provide more effectivebleaching. Furthermore, in alternative embodiments where a peroxy acidserves as the peroxide compound, the oxidizing strength of the oral carecomposition is increased due to the leaving qualities of theRCO₂-component of the peroxy acid.

In various embodiments, the compositions comprise a non-peroxidewhitening agent. Non-peroxide whitening agents among those useful hereininclude non-peroxy compounds, such as chlorine dioxide, chlorites andhypochlorites. Chlorites and hypochlorites include those of alkali andalkaline earth metals such as lithium, potassium, sodium, magnesium,calcium and barium. Non-peroxide whitening agents also includecolorants, such as titanium dioxide and hydroxyapatite.

The whitening agent preferably comprises from about 0.1% to about 20% ofthe oral care composition. In a preferred embodiment, the peroxidecompound comprises from about 1% to about 10% of the oral carecomposition.

Orally Acceptable Carrier

The present invention provides compositions comprising an orallyacceptable carrier. As used herein, an “orally acceptable carrier”refers to a material or combination of materials that are safe for usein the compositions of the present invention, commensurate with areasonable benefit/risk ratio, with which the peroxide complex andwhitening agent may be associated while retaining significant efficacy.Preferably, the carrier does not substantially reduce the efficacy ofthe peroxide complex or whitening agent. Selection of specific carriercomponents is dependant on the desired product form, includingdentifrices, rinses, gels, and paints. In various embodiments, thecarrier is operable to sufficiently adhere the peroxide complex againstsurfaces within the oral cavity to which the composition isadministered, without concomitant use of a dental tray, mouthpiece,tape, or similar appliance. In various embodiments, the carrier isoperable for use with a tape, tray, mouthpiece or similar appliance.

Materials among those that are useful in carriers include adhesionagents, viscosity modifiers, diluents, surfactants, foam modulators,peroxide activators, peroxide stability agents, abrasives, pH modifyingagents, humectants, mouth feel agents, sweeteners, flavorants,colorants, and combinations thereof. It is understood that while generalattributes of each of the above categories of materials may differ,there may be some common attributes and any given material may servemultiple purposes within two or more of such categories of materials.Preferably, such carrier materials are selected for compatibility withthe peroxide complex and with other ingredients of the composition.

In various embodiments, the carrier comprises an adhesion agent. Asreferred to herein, an adhesion agent is a material or combination ofmaterials that enhance the retention of the peroxide complex on the oralcavity surface onto which the composition is applied. Such adhesionagents include adhesives, film forming materials, viscosity enhancersand combinations thereof. Such materials include hydrophilic organicpolymers, hydrophobic organic polymers, silicone gums, siliconeadhesives, silicas, and combinations thereof. Adhesion agents arepreferably present at a level of from about 0.01% to about 75%,optionally from about 1% to about 40%. Accordingly, the presentinvention provides oral care compositions comprising:

-   -   (a) a peroxide complex comprising hydrogen peroxide and an        N-vinyl heterocyclic polymer;    -   (b) whitening agent; and    -   (c) an orally acceptable non-aqueous carrier.

Hydrophilic organic polymers useful herein include polyethylene glycols,nonionic polymers of ethylene oxide, block copolymers of ethylene oxideand propylene oxide, carboxymethylene polymers, N-vinyl heterocyclicpolymers, and mixtures thereof. Nonaqueous hydrophilic polymers usefulin the practice of the present invention preferably provide a viscosityfor the composition in the range between about 10,000 cps to 600,000cps.

Hydrophilic polymers also include polymers of polyethylene glycols andethylene oxide having the general formula:

HOCH₂(CH₂OCH₂)_(n)OH

wherein n represents the average number of oxyethylene groups.Polyethylene glycols available from Dow Chemical (Midland, Mich.,U.S.A.) are designated by number such as 200, 300, 400, 600, 2000 whichrepresents the approximate average molecular weight of the polymer.Polyethylene glycols 200, 300, 400 and 600 are clear viscous liquids atroom temperature, and are preferred for use in the practice of thepresent invention.

Another hydrophilic polymer useful herein is comprised of a watersoluble, nonionic block copolymer of ethylene oxide and propylene oxideof the formula: HO(C₂H₄O)_(a)(C₃H₆O)_(b)(C₂H₄O)_(c)H. The blockcopolymer is preferably chosen (with respect to a, b and c) such thatthe ethylene oxide constituent comprises from about 65 to about 75% byweight, of said copolymer molecule and the copolymer has an averagemolecular weight of from about 2,000 to about 15,000, with the copolymerbeing present in oral care composition in such concentration that thecomposition is liquid at room temperature (23° C.).

A block copolymer useful herein is Pluraflo L1220 (marketed by BASF,Mount Olive, N.J., U.S.A.), which has an average molecular weight ofabout 9,800. The hydrophilic poly(ethylene oxide) block averages about65% by weight of the polymer.

Organic polymers useful as adhesion enhancing agents include hydrophilicpolymers such as carbomers such as carboxymethylene polymers such asacrylic acid polymers, and acrylic acid copolymers. Carboxypolymethyleneis a slightly acidic vinyl polymer with active carboxyl groups. One suchcarboxypolymethylene is Carbopol® 974 marketed by Noveon, Inc.,Cleveland, Ohio, U.S.A.

In one embodiment, the compositions comprise an N-vinyl heterocyclicpolymer in addition to the N-vinyl heterocyclic polymer that is acomponent of the peroxide complex. Such N-vinyl heterocyclic polymersinclude those discussed above. In one embodiment, the N-vinylheterocyclic polymer is the same as that which is a component of theperoxide complex. In one embodiment, the N-vinyl heterocyclic polymer isdifferent that that which is a component of the peroxide complex. In apreferred embodiment, the polymer is poly-N-vinyl-poly-2-pyrrolidone,preferably polyvinylpyrrolidone, cross-povidone, and cPVP

Hydrophobic organic materials useful as adhesion enhancing agents in thepractice of the present invention include hydrophobic materials such aswaxes such as bees wax, mineral oil, mineral oil and polyethylene blends(Plastigel® marketed by Lyne Laboratories, Brockton, Mass., USA.),petrolatum, white petrolatum, liquid paraffin, butane/ethylene/styrenehydrogenated copolymer) blends (Versagel® marketed by Penreco, Houston,Tex., U.S.A.), acrylate and vinyl acetate polymers and copolymers,polyethylene waxes, silicone polymers as discussed further herein andpolyvinyl pyrrolidone/vinyl acetate copolymers. In embodiments of thepresent invention containing a hydrophobic polymer, present in ratios ofabout 1 to about 85% weight of the composition.

Silicone polymers useful herein include, but are not limited to,silicone adhesives, silicone elastomers, silicone fluids, siliconeresins, silicone gums and mixtures thereof. In one embodiment, thecarrier comprises a pressure sensitive adhesive (PSA) composition,including those that are well known in the art. Generally, siliconebased PSA's are produced by condensing a silicone resin and anorganosiloxane such as a polydiorganosilioxane. Suitable siliconepolymers include the copolymer product of mixing a silanol terminatedpolydiorganosiloxane such as polydimethyl siloxane with asilanol-containing silicone resin whereby the silanol groups of thepolydiorganosiloxane undergo a condensation reaction with the silanolgroups of the silicone resin so that the polydiorganosiloxane is lightlycrosslinked by the silicone resin (that is, the polydiorganosiloxanechains are bonded together through the resin molecules to give chainbranching and entanglement and/or a small amount of network character)to form the silicone pressure sensitive adhesive. A catalyst, forexample an alkaline material such as ammonia, ammonium hydroxide orammonium carbonate, can be mixed with the silanol-terminatedpolydiorganosiloxane and the silicone resin to promote this crosslinkingreaction. Copolymerizing the silicone resin with the silanol terminatedpolydiorganosiloxane affords a self adhering and cohesive soft elastomermatrix. Modifying the silicone resin to polydiorganosiloxane ratio ofthe pressure sensitive adhesive will modify the tackiness of the oralcare composition. For example PSAs are available from the Dow-CorningCorporation, Midland, Mich., U.S.A., under the brand name BIO-PSA. Thesilicone based pressure sensitive adhesive is present in the liquidwhitening compositions of the present invention at a concentration ofabout 0.5% to about 99%, optionally from about 5% to about 60%,optionally from about 10% to about 40%.

Silicone gums useful herein include high molecular weightpolydiorganosiloxanes having a viscosity at 25° C. of from about 500,000cS up to about 50,000,000 cS. Such silicone gums include thosepolydiorganosiloxanes with an average molecular weight of greater than500,000. The polysiloxane gums for use herein can be linear or cyclic,and branched or unbranched. Substituents may have any structure as longas the resulting polysiloxanes are hydrophobic, are not irritating,toxic or otherwise harmful when applied to the oral cavity, and arecompatible with the other components of the composition, Specificexamples of siloxane gums include polydimethylsiloxane,methylvinylsiloxane, copolymer, poly(dimethylsiloxane, diphenyl,methyvinylsiloxane) copolymer, and mixtures thereof. Silicone gumsinclude those commercially available, such as SE30, marketed by GeneralElectric.

Polysiloxane fluids useful herein include those with a viscosity, at 25°C., of from about 1 cS to about 1000 cS, preferably from about 2 cS toabout 500 cS, and optionally from about 5 cS to about 400 cS.Polysiloxane fluids for use herein can be linear or cyclic, and can besubstituted with a wide variety of substituents (including as describedabove). Preferred substituents include methyl, ethyl and phenylsubstituents. Suitable polysiloxane fluids include linear polysiloxanepolymers such as dimethicone and other low viscosity analogues of thepolysiloxane materials, preferably having a viscosity at 25° C. of 200cS or less and cyclomethicone, and other cyclic siloxanes having forexample a viscosity at 25° C. of 200 cS or less. Commercial examples ofmaterials that are suitable for use herein include DC200 series fluidsmarketed by Dow-Corning Corporation and the AK Fluid series marketed byWacker-Chemie GmbH, München, Germany.

Adhesion agents also include inorganic materials. Such inorganicmaterials include silicon polymers such as amorphous silica compoundswhich function as thickening agents (Cab-o-sil® fumed silicamanufactured by Cabot Corporation, Boston, Mass., U.S.A.; and Sylox 15also known as Sylodent 15, marketed by Davison Chemical Division of W.R.Grace & Co., Columbia, Md., U.S.A.).

Thickening agents among those useful herein include carboxyvinylpolymers, carrageenans (also known as Irish moss and more particularlyiota-carrageenan), cellulosic polymers such as hydroxyethylcellulose,carboxymethylcellulose (carmellose) and salts thereof (e.g., carmellosesodium), natural gums such as karaya, xanthan, gum arabic andtragacanth, colloidal magnesium aluminum silicate, colloidal silica, andmixtures thereof. One or more thickening agents are optionally presentin a total amount of about 0.01% to about 15%, for example about 0.1% toabout 10% or about 0.2% to about 5% by weight of the composition.

Viscosity modifiers among those useful herein include mineral oil,petrolatum, clays and organomodified clays, silica, and mixturesthereof. In various embodiments, such viscosity modifiers are operableto inhibit settling or separation of ingredients or to promoteredispersibility upon agitation of a liquid composition. One or moreviscosity modifiers are optionally present in a total amount of about0.01% to about 10%, for example about 0.1% to about 5% by weight of thecomposition.

Diluents among those useful herein include materials or combinations ofmaterials that are operable to solubilize and/or suspend othercomponents of the composition. In various embodiments, diluents areoperable to adjust the viscosity of the composition, optionally inconjunction with viscosity modifiers (as discussed herein) and othercomponents of the composition. The composition is preferablynon-aqueous, i.e., does not contain appreciable amounts ofchemically-unbound water in addition to water added consequent to theperoxide compound. Preferably, the composition comprises less than about5% water in the carrier. Diluents among those useful herein includeglycerin and lower alcohols (e.g., C₁-C₅ alcohol, preferably ethanol).Diluents are present in the nonaqueous liquid whitening compositions ofthe present invention in amounts of about 0.1% to about 90%, optionallyin various embodiments from about 0.5% to about 70%, from about 0.5% toabout 50%, from about 0.5% to about 35%.

Surfactants among those useful herein include anionic, nonionic, andamphoteric surfactants. Surfactants may be used, for example, to provideenhanced stability of the formulation, to help in cleaning the oralcavity surfaces through detergency, and to provide foam upon agitation,e.g., during brushing with a dentifrice composition of the invention.Suitable anionic surfactants include water-soluble salts of C₈₋₂₀ alkylsulfates, sulfonated monoglycerides of C₈₋₂₀ fatty acids, sarcosinates,taurates, and mixtures thereof. Illustrative examples of these and othersurfactants are sodium lauryl sulfate, sodium coconut monoglyceridesulfonate, sodium lauryl sarcosinate, sodium lauryl isoethionate, sodiumlaureth carboxylate and sodium dodecyl benzenesulfonate, and mixturesthereof. Suitable nonionic surfactants include xpoloxamers,polyoxyethylene sorbitan esters, fatty alcohol ethoxylates, alkylphenolethoxylates, tertiary amine oxides, tertiary phosphine oxides, dialkylsulfoxides, and mixtures thereof. Suitable amphoteric surfactantsinclude derivatives of C₈₋₂₀ aliphatic secondary and tertiary amineshaving an anionic group such as carboxylate, sulfate, sulfonate,phosphate or phosphonate. A suitable example is cocoamidopropylbetaine.One or more surfactants are optionally present in a total amount ofabout 0.01% to about 10%, for example about 0.05% to about 5% or about0.1% to about 2%. Preferably, the surfactant is nonionic and compatiblewith peroxide compounds such as polyethylene oxide. Nonionic surfactantsare present in embodiments of this invention at levels of from about0.01% to about 1%.

Foam modulators useful herein include materials operable to increaseamount, thickness or stability of foam generated by the composition(e.g., dentifrice compositions) upon agitation. Any orally acceptablefoam modulator can be used, including polyethylene glycols (PEGs), alsoknown as polyoxyethylenes. High molecular weight PEGs are suitable,including those having an average molecular weight of about 200,000 toabout 7,000,000, for example about 500,000 to about 5,000,000 or about1,000,000 to about 2,500,000. One or more PEGs are optionally present ina total amount of about 0.1% to about 10%, for example about 0.2% toabout 5% or about 0.25% to about 2%.

Humectants useful herein include polyhydric alcohols such as glycerin,sorbitol, xylitol or low molecular weight PEGs. In various embodiments,humectants are operable to prevent hardening of paste or gelcompositions upon exposure to air. In various embodiments humectantsalso function as sweeteners. One or more humectants are optionallypresent in a total amount of about 1% to about 50%, for example about 2%to about 25% or about 5% to about 15%.

Peroxide activators such as sodium bicarbonate, sodium carbonate,manganese gluconate may be incorporated in the compositions of thepresent invention. The activator is relatively nonactive with theperoxide whitening agent in nonaqueous liquid compositions. In variousembodiments, the activator is operable to react with the peroxide torelease oxygen when the liquid whitening composition applied to theteeth is contacted with saliva in the oral cavity. The peroxideactivator is optionally present in embodiments of this invention at aconcentration of about 0.1% to about 50%.

pH modifying agents among those useful herein include acidifying agentsto lower pH, basifying agents to raise pH, and buffering agents tocontrol pH within a desired range. For example, one or more compoundsselected from acidifying, basifying and buffering agents can be includedto provide a pH of about 2 to about 10, or in various embodiments fromabout 2 to about 8, from about 3 to about 9, from about 4 to about 8,from about 5 to about 7, from about 6 to about 10, and from about 7 toabout 9. Any orally acceptable pH modifying agent can be used, includingcarboxylic, phosphoric and sulfonic acids, acid salts (e.g., monosodiumcitrate, disodium citrate, monosodium malate, etc.), alkali metalhydroxides such as sodium hydroxide, carbonates such as sodiumcarbonate, bicarbonates, sesquicarbonates, borates, silicates,phosphates (e.g., monosodium phosphate, trisodium phosphate,pyrophosphate salts, etc.), imidazole, and mixtures thereof. One or morepH modifying agents are optionally present in a total amount effectiveto maintain the composition in an orally acceptable pH range.

Mouth-feel agents include materials which impart a desirable texture orother feeling during use of the composition. Such agents includebicarbonate salts, which in various embodiments impart a “clean feel” toteeth and gums due to effervescence and release of carbon dioxide. Anyorally acceptable bicarbonate can be used, including without limitationalkali metal bicarbonates such as sodium and potassium bicarbonates,ammonium bicarbonate, and mixtures thereof. One or more bicarbonatesalts are optionally present in a total amount of 0.1% to about 50%, forexample about 1% to about 20%.

Flavorants among those useful herein include any material or mixture ofmaterials operable to enhance the taste of the composition. Any orallyacceptable natural or synthetic flavorant can be used, such as flavoringoils, flavoring aldehydes, esters, alcohols, similar materials, andcombinations thereof. Flavorants include vanillin, sage, marjoram,parsley oil, spearmint oil, cinnamon oil, oil of wintergreen(methylsalicylate), peppermint oil, clove oil, bay oil, anise oil,eucalyptus oil, citrus oils, fruit oils and essences including thosederived from lemon, orange, lime, grapefruit, apricot, banana, grape,apple, strawberry, cherry, pineapple, etc., bean- and nut-derivedflavors such as coffee, cocoa, cola, peanut, almond, etc., adsorbed andencapsulated flavorants, and mixtures thereof. Also encompassed withinflavorants herein are ingredients that provide fragrance and/or othersensory effect in the mouth, including cooling or warming effects. Suchingredients include methol, menthyl acetate, menthyl lactate, camphor,eucalyptus oil, eucalyptol, anethole, eugenol, cassia, oxanone,α-irisone, propenyl guaiethol, thymol, linalool, benzaldehyde,cinnamaldehyde, N-ethyl-p-menthan-3-carboxamine,N,2,3-trimethyl-2-isopropylbutanamide, 3-1-menthoxypropane-1,2-diol,cinnamaldehyde glycerol acetal (CGA), methone glycerol acetal (MGA), andmixtures thereof. One or more flavorants are optionally present in atotal amount of about 0.01% to about 5%, optionally in variousembodiments from about 0.05 to about 2%, from about 0.1% to about 2.5%,and from about 0.1 to about 0.5%.

Sweeteners among those useful herein include orally acceptable naturalor artificial, nutritive or non-nutritive sweeteners. Such sweetenersinclude dextrose, polydextrose, sucrose, maltose, dextrin, dried invertsugar, mannose, xylose, ribose, fructose, levulose, galactose, cornsyrup (including high fructose corn syrup and corn syrup solids),partially hydrolyzed starch, hydrogenated starch hydrolysate, sorbitol,mannitol, xylitol, maltitol, isomalt, aspartame, neotame, saccharin andsalts thereof, sucralose, dipeptide-based intense sweeteners,cyclamates, dihydrochalcones, and mixtures thereof. One or moresweeteners are optionally present in a total amount depending stronglyon the particular sweetener(s) selected, but typically at levels of fromabout 0.005% to about 5%, optionally from about 0.01% to about 1%.

Colorants among those useful herein include pigments, dyes, lakes andagents imparting a particular luster or reflectivity such as pearlingagents. In various embodiments, colorants are operable to provide awhite or light-colored coating on a dental surface, to act as anindicator of locations on a dental surface that have been effectivelycontacted by the composition, and/or to modify appearance, in particularcolor and/or opacity, of the composition to enhance attractiveness tothe consumer. Any orally acceptable colorant can be used, including FD&Cdyes and pigments, talc, mica, magnesium carbonate, calcium carbonate,magnesium silicate, magnesium aluminum silicate, silica, titaniumdioxide, zinc oxide, red, yellow, brown and black iron oxides, ferricammonium ferrocyanide, manganese violet, ultramarine, titaniated mica,bismuth oxychloride, and mixtures thereof. One or more colorants areoptionally present in a total amount of about 0.001% to about 20%, forexample about 0.01% to about 10% or about 0.1% to about 5%.

In one embodiment, the present invention provides compositionscomprising:

(a) from about 0.5% to about 60% of a peroxide complex

(b) from about 0.5% to about 60% of a whitening agent; and

(c) from about 0.5% to about 60% of a silicone adhesive.

Optionally, the composition additionally comprises from about 1 to about99% of a silicone fluid. Optionally, the composition additionallycomprises from about 1% to about 40% of a hydrophobic polymer, such as ablend of mineral oil and polyethylene glycol.

Optional Active Materials:

The compositions of the present invention optionally comprise an activematerial, which is operable for the prevention or treatment of acondition or disorder of hard or soft tissue of the oral cavity, theprevention or treatment of a physiological disorder or condition, or toprovide a cosmetic benefit. In various embodiments, the active is a“systemic active” which is operable to treat or prevent a disorderwhich, in whole or in part, is not a disorder of the oral cavity. Invarious embodiments, the active is an “oral care active” operable totreat or prevent a disorder or provide a cosmetic benefit within theoral cavity (e.g., to the teeth, gingiva or other hard or soft tissue ofthe oral cavity). Oral care actives among those useful herein includewhitening agents, anticaries agents, tartar control agents, antiplaqueagents, periodontal actives, abrasives, breath freshening agents,malodour control agents, tooth desensitizers, salivary stimulants, andcombinations thereof. It is understood that while general attributes ofeach of the above categories of actives may differ, there may somecommon attributes and any given material may serve multiple purposeswithin two or more of such categories of actives. Preferably, suchactives are selected for compatibility with the peroxide complex,peroxide compound, and other ingredients of the composition. Activesamong those useful herein are disclosed in U.S. Patent Publication2003/0206874, Doyle et al., published Nov. 6, 2003; U.S. Pat. No.6,290,933, Durga et al., issued Sep. 18, 2001; and U.S. Pat. No.6,685,921, Lawlor, issued Feb. 3, 2004.

Actives useful herein are optionally present in the compositions of thepresent invention in safe and effective amounts. A “safe and effective”amount of an active is an amount that is sufficient to have the desiredtherapeutic or prophylactic effect in the human or lower animal subjectto whom the active is administered, without undue adverse side effects(such as toxicity, irritation, or allergic response), commensurate witha reasonable benefit/risk ratio when used in the manner of thisinvention. The specific safe and effective amount of the active willvary with such factors as the particular condition being treated, thephysical condition of the subject, the nature of concurrent therapy (ifany), the specific active used, the specific dosage form, the carrieremployed, and the desired dosage regimen.

The compositions of the present invention optionally comprise anabrasive. In various embodiments, an abrasive is useful for example as apolishing agent. Any orally acceptable abrasive can be used, but type,fineness (particle size) and amount of abrasive should be selected sothat tooth enamel is not excessively abraded in normal use of thecomposition. Suitable abrasives include silica, for example in the formof silica gel, hydrated silica or precipitated silica, alumina,insoluble phosphates, calcium carbonate, resinous abrasives such asurea-formaldehyde condensation products, and mixtures thereof. Amonginsoluble phosphates useful as abrasives are orthophosphates,polymetaphosphates and pyrophosphates. Illustrative examples aredicalcium orthophosphate dihydrate, calcium pyrophosphate, β-calciumpyrophosphate, tricalcium phosphate, calcium polymetaphosphate andinsoluble sodium polymetaphosphate. One or more abrasives are optionallypresent in an abrasive effective total amount, typically about 5% toabout 70%, for example about 10% to about 50% or about 15% to about 30%by weight of the composition. Average particle size of an abrasive, ifpresent, is generally about 0.1 to about 30 μm, for example about 1 toabout 20 μm or about 5 to about 15 μm.

The compositions of the present invention optionally comprise a tartarcontrol (anticalculus) agent. Tartar control agents among those usefulherein include phosphates and polyphosphates (for examplepyrophosphates), polyaminopropanesulfonic acid (AMPS), polyolefinsulfonates, polyolefin phosphates, diphosphonates such asazacycloalkane-2,2-diphosphonates (e.g.,azacycloheptane-2,2-diphosphonic acid), N-methylazacyclopentane-2,3-diphosphonic acid, ethane-1-hydroxy-1,1-diphosphonicacid (EHDP) and ethane-1-amino-1,1-diphosphonate, phosphonoalkanecarboxylic acids and salts of any of these agents, for example theiralkali metal and ammonium salts. Useful inorganic phosphate andpolyphosphate salts include monobasic, dibasic and tribasic sodiumphosphates, sodium tripolyphosphate, tetrapolyphosphate, mono-, di-,tri- and tetrasodium pyrophosphates, sodium trimetaphosphate, sodiumhexametaphosphate and mixtures thereof, wherein sodium can optionally bereplaced by potassium or ammonium. Other useful anticalculus agentsinclude polycarboxylate polymers and polyvinyl methyl ether/maleicanhydride (PVME/MA) copolymers, such as those available under theGantrez™ brand from ISP, Wayne, N.J. One or more anticalculus agents areoptionally present in an anticalculus effective total amount, typicallyabout 0.01% to about 50%, for example about 0.05% to about 25% or about0.1% to about 15%.

The compositions of the present invention optionally comprise a fluorideion source useful, for example, as an anti-caries agent. Any orallyacceptable fluoride ion source can be used, including potassium, sodiumand ammonium fluorides and monofluorophosphates, stannous fluoride,indium fluoride, and mixtures thereof. In various embodiments,water-soluble fluoride ion sources are used. One or more fluoride ionsources are optionally present in an amount providing a total of about0.0025% to about 2%, for example about 0.005% to about 1% or about 0.01%to about 0.3%, of fluoride ions.

The compositions of the present invention optionally comprise a stannousion source useful, for example, as a periodontal active, tartar controlagent, anticaries agent or tooth desensitizer. Any orally acceptablestannous ion source can be used, including stannous fluoride, otherstannous halides such as stannous chloride dihydrate, organic stannouscarboxylate salts such as stannous formate, acetate, gluconate, lactate,tartrate, oxalate, malonate and citrate, stannous ethylene glyoxide, andmixtures thereof. One or more stannous ion sources are optionallypresent in a total amount of from about 0.01% to about 10%, optionallyfrom about 0.1% to about 7% or from about 1% to about 5%.

The compositions of the present invention optionally comprise anantimicrobial (e.g., antibacterial) agent. Any orally acceptableantimicrobial agent can be used, including triclosan(5-chloro-2-(2,4-dichlorophenoxyl)phenol); 8-hydroxyquinoline and saltsthereof; zinc and stannous ion sources such as zinc citrate, zincsulphate, zinc glycinate, sodium zinc citrate and stannouspyrophosphate; copper (II) compounds such as copper (II) chloride,fluoride, sulfate and hydroxide; phthalic acid and salts thereof such asmagnesium monopotassium phthalate; sanguinarine; quaternary ammoniumcompounds, such as alkylpyridinium chlorides (e.g., cetylpyridiniumchloride (CPC), combinations of CPC with zinc and/or enzymes,tetradecylpyridinium chloride, and N-tetradecyl-4-ethylpyridiniumchloride,); bisguanides, such as chlorhexidine digluconate, hexetidine,octenidine, and alexidine; halogenated bisphenolic compounds, such as2,2′ methylenebis-(4-chloro-6-bromophenol); benzalkonium chloride;salicylanilide, domiphen bromide; iodine; sulfonamides; bisbiguanides;phenolics; piperidino derivatives such as delmopinol and octapinol;magnolia extract; grapeseed extract; thymol; eugenol; menthol; geraniol;carvacrol; citral; eucalyptol; catechol; 4-allylcatechol; hexylresorcinol; methyl salicylate; antibiotics such as augmentin,amoxicillin, tetracycline, doxycycline, minocycline, metronidazole,neomycin, kanamycin and clindamycin; and mixtures thereof. A furtherillustrative list of useful antibacterial agents is provided in U.S.Pat. No. 5,776,435, Gaffar, et al., issued Jul. 7, 1998.

The compositions of the present invention optionally comprise anantioxidant. Any orally acceptable antioxidant can be used, includingbutylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), vitaminA, carotenoids, vitamin E, flavonoids, polyphenols, ascorbic acid,herbal antioxidants, chlorophyll, melatonin, and mixtures thereof.

The compositions of the present invention optionally comprise a salivastimulating agent, useful for example in amelioration of dry mouth. Anyorally acceptable saliva stimulating agent can be used, includingwithout limitation food acids such as citric, lactic, malic, succinic,ascorbic, adipic, fumaric and tartaric acids, and mixtures thereof. Oneor more saliva stimulating agents are optionally present in a salivastimulating effective total amount.

The compositions of the present invention optionally comprise a breathfreshening agent. Any orally acceptable breath freshening agent can beused, including without limitation zinc salts such as zinc gluconate,zinc citrate and zinc chlorite, α-ionone, and mixtures thereof. One ormore breath freshening agents are optionally present in a breathfreshening effective total amount.

The compositions of the present invention optionally comprise anantiplaque (e.g., plaque disrupting) agent. Any orally acceptableantiplaque agent can be used, including without limitation stannous,copper, magnesium and strontium salts, dimethicone copolyols such ascetyl dimethicone copolyol, papain, glucoamylase, glucose oxidase, urea,calcium lactate, calcium glycerophosphate, strontium polyacrylates, andmixtures thereof.

The compositions of the present invention optionally comprise ananti-inflammatory agent. Any orally acceptable anti-inflammatory agentcan be used, including steroidal agents such as flucinolone andhydrocortisone, and nonsteroidal agents (NSAIDs) such as ketorolac,flurbiprofen, ibuprofen, naproxen, indomethacin, diclofenac, etodolac,indomethacin, sulindac, tolmetin, ketoprofen, fenoprofen, piroxicam,nabumetone, aspirin, diflunisal, meclofenamate, mefenamic acid,oxyphenbutazone and phenylbutazone, and mixtures thereof.

The compositions of the present invention optionally comprise comprisean H₂ antagonist. H₂ antagonists useful herein include cimetidine,etintidine, ranitidine, ICIA-5165, tiotidine, ORF-17578, lupititidine,donetidine, famotidine, roxatidine, pifatidine, lamtidine, BL-6548,BMY-25271, zaltidine, nizatidine, mifentidine, BMY-52368, SKF-94482,BL-6341A, ICI-162846, ramixotidine, Wy-45727, SR-58042, BMY-25405,loxtidine, DA-4634, bisfentidine, sufotidine, ebrotidine, HE-30-256,D-16637, FRG-8813, FRG-8701, impromidine, L-643728, HB-408.4, andmixtures thereof.

The compositions of the present invention optionally comprise adesensitizing agent. Desensitizing agents useful herein includepotassium citrate, potassium chloride, potassium tartrate, potassiumbicarbonate, potassium oxalate, potassium nitrate, strontium salts, andmixtures thereof. Alternatively or in addition a local or systemicanalgesic such as aspirin, codeine, acetaminophen, sodium salicylate ortriethanolamine salicylate can be used.

The compositions of the present invention optionally comprise anutrient. Suitable nutrients include vitamins, minerals, amino acids,and mixtures thereof. Vitamins include Vitamins C and D, thiamine,riboflavin, calcium pantothenate, niacin, folic acid, nicotinamide,pyridoxine, cyanocobalamin, para-aminobenzoic acid, bioflavonoids, andmixtures thereof. Nutritional supplements include amino acids (such asL-tryptophane, L-lysine, methionine, threonine, levocarnitine andL-carnitine), lipotropics (such as choline, inositol, betaine, andlinoleic acid), fish oil (including components thereof such as omega-3(N-3) polyunsaturated fatty acids, eicosapentaenoic acid anddocosahexaenoic acid), coenzyme Q10, and mixtures thereof.

The compositions of the present invention optionally comprise proteins.Suitable proteins include milk proteins and enzymes such asperoxide-producing enzymes, amylase, plaque-disrupting agents such aspapain, glucoamylase, glucose oxidase, and “next generation” enzymes.”

Methods of Manufacture:

The liquid whitening compositions of the present invention are made byany of a variety of methods, including adding and mixing the ingredientsof the composition in a suitable vessel such as a stainless steel tankprovided with a mixer. In one embodiment, a whitening agent, siliconeadhesive and carrier fluid are mixed to form a homogenous mixture. Theperoxide complex is then added to the homogenous mixture and the newlyformed composition is mixed under a vacuum. In one embodiment, theliquid ingredients are combined (e.g., in the order of whitening agentsuch as liquid hydrogen peroxide, silicone fluid, silicone adhesivefluid and Pluracare), and mixed at high speed for 30 minutes. Plastigel(if present) is then added and the solution is mixed at high speed forfive minutes. Finally, the peroxide complex is added and the compositionis mixed at high speed for fifteen minutes under vacuum. Additionalingredients such as flavorant, coloring or sweeteners are added at anypoint during the mixing process but in various embodiments suchingredients are preferably added last or close to last. In someembodiments, the peroxide complex is formed in situ, such that themethod comprises mixing a peroxide component (e.g., solution of hydrogenperoxide) and N-vinyl heterocyclic polymer (e.g., cPVP), with anadditional quantity of peroxide compound. In other embodiments, theperoxide complex is formed prior to addition to the remainder of thecomposition.

Methods

The present invention provides methods for whitening a tooth surfaceusing compositions according to the present invention. As referred toherein, “tooth” or “teeth” refers to natural teeth, dentures, dentalplates, fillings, caps, crowns, bridges, dental implants, and the like,and any other hard surfaced dental prosthesis either permanently ortemporarily fixed within the oral cavity. As used herein, “whitening”refers to a change in visual appearance of a tooth, preferably such thatsuch that the tooth has a brighter shade.

Increase in whiteness of a dental surface can be observed visually, forexample with the aid of color comparison charts or gauges, or measuredby colorimetry, using any suitable instrument such as a MinoltaChromameter, e.g., model CR-400 (Minolta Corp., Ramsey, N.J.). Theinstrument can be programmed, for example, to measure Hunter Lab valuesor L*a*b* values according to the standard established by theInternational Committee of Illumination (CIE). The L*a*b* systemprovides a numerical representation of three-dimensional color spacewhere L* represents a lightness axis, a* represents a red-green axis andb* represents a yellow-blue axis. The L* and b* axes are typically ofgreatest applicability to measurement of tooth whiteness. Increase inwhiteness can be computed from differences in L*, a* and b* valuesbefore and after treatment, or between untreated and treated surfaces. Auseful parameter is ΔE*, calculated as the square root of the sum of thesquares of differences in L*, a* and b* values, using the formula:

ΔE*=[(ΔL*)2+(Δa*)2+(Δb*)2]½

A higher value of ΔE* indicates greater increase in whiteness. Invarious embodiments, the method of the present invention can effect aΔE* of at least about 1, or at least about 3, or at least about 4, or atleast about 5.

Accordingly, the present invention provides methods for whitening atooth surface, comprising applying to the surface a safe and effectiveamount of a mixture of a peroxide complex comprising a peroxide compoundand a porous cross-linked polymer and a whitening agent. Preferably themethod comprises applying a composition of the present invention,comprising the peroxide complex, whitening agent, and a carrier. Asreferred to herein, “applying” refers to any method by which theperoxide complex is placed in contact with the tooth surface. Suchmethods, in various embodiments, comprise direct application of acomposition by such methods as rinsing, painting, and brushing. Invarious embodiments, application of the composition comprises the use ofan application device which aids in maintaining contact of the compositeto the tooth surface for sufficient time so as to allow whitening.

Suitable application devices include dental trays, mouthpieces, floss,fibers, chips, strips and tapes. Strips among those useful hereincomprise polymers, natural and synthetic woven materials, non-wovenmaterial, foil, paper, rubber and combinations thereof. Preferably thestrip of material is substantially water insoluble. Suitable polymersinclude polyethylene, ethylvinylacetate, polyesters, ethylvinyl alcohol,fluoroplastics, and combinations thereof In various embodiments, thestrip of material is generally less than about 1 mm (millimeter) thick,optionally less than about 0.05 mm thick, optionally about 0.001 toabout 0.03 mm thick. The shape of the strip is any shape and size thatcovers the desired oral surface. In one embodiment, the length of thestrip material is from about 2 cm (centimeter) to about 12 cm, inanother embodiment from about 4 cm to about 9 cm. The width of the stripmaterial will also depend on the oral surface area to be covered. Thewidth of the strip is generally from about 0.5 cm to about 4 cm, in oneembodiment from about 1 cm to about 2 cm. The strip material maycomprise shallow pockets, optionally filled by a composition of thisinvention so as to provide reservoirs of peroxide complex. Strips amongthose useful herein are disclosed in U.S. Pat. No. 6,514,484, Rajaiah etal. issued Feb. 4, 2003.

In one preferred embodiment, the whitening composition is applied usinga “paint on” technique. A small application device, such as a brush orspatula is coated with a composition of this invention and thecomposition is then placed on a tooth surface. Preferably, thecomposition be spread evenly on such surfaces, in sufficient quantity todeliver a whitening amount of peroxide complex.

The present invention also provides methods for effecting the controlledrelease of an oxidizing peroxide species onto a tooth surface,comprising contacting the surface with a mixture of a peroxide complexand whitening agent of the present invention. As referred to herein,such controlled release in various embodiments comprises release of theperoxide over a time sufficient to effect whitening of the teeth.Without limiting the mechanism, function or utility of presentinvention, in some embodiments contact with saliva causes the release ofan effective amount of peroxide active from the cross-linked polymermatrix to the applied tooth site over a period of time. Preferably, thecomposition is contacted with the tooth surface for at least about 30seconds, optionally at least about 1 minute.

In various embodiments, it is preferred that the subject does not eat ordrink while the composition is in contact with the dental surface. Thewhitening composition can be removed as and when required, at will, byan employment of standard oral hygiene procedures such as brushing or byrinsing, e.g., with a mouthwash. The process can be repeated severaltimes until the desired whitening results are achieved.

In various embodiments, compositions of the present invention are alsoused for the treatment or prevention of disorders in the oral cavity,including cavity prevention, whitening, plaque prevention or reduction,gingivitis prevention or reduction, tartar control, sensitivityprevention or reduction, breath malodor prevention or reduction, andstain prevention. Compositions of the present invention may also be usedfor the treatment or prevention of systemic disorders, such as theimprovement of overall systemic health characterized by a reduction inrisk of development of systemic diseases, such as cardiovasculardisease, stroke, diabetes, severe respiratory infection, premature andlow birth weight infants (including associated post-partum dysfunctionin neurologic/developmental function), and associated increased risk ofmortality. Such methods include those disclosed in U.S. PatentPublication 2003/0206874, Doyle et al., published Nov. 6, 2003.

The present invention is further illustrated through the followingnon-limiting examples.

Example 1

A composition of the present invention is made, as follows:

Ingredients Weight % cPVP-H₂O₂ powder 25 35% Hydrogen Peroxide aqueoussolution 4 DC Silicone Fluid - 350 CST 20 (Dimethylsiloxane) DC 8-7016Fluid (Silicone Adhesive) 30 Plastigel 5 20.1 Sodium Saccharin 0.3 MintFlavor 0.6 Total (%) 100

The liquid hydrogen peroxide, DC silicone fluid, and silicone adhesiveare combined and mixed at high speed for 30 minutes. The Plastigel isthen added and the solution is mixed at high speed for five minutes.Finally, the peroxide complex, flavorant and sweetener are added and thecomposition is mixed at high speed for 20 minutes under vacuum until thecomposition is homogenous.

The composition is applied to the teeth of a human subject havingstained teeth, resulting in perceptible whitening.

Example 2

A composition of the present invention is made, as follows:

Ingredients Weight % cPVP-H₂O₂ powder 10 sodium percarbonate 25 DCSilicone Fluid - 350 CST 16.55 (Dimethylsiloxane) DC 8-7016 Fluid(Silicone Adhesive) 30 Pluracare L-1220 1 Plastigel 5 16.55 sodiumsaccharin 0.3 mint flavor 0.6 Total (%) 100

The composition is made by a process generally as described above inExample 1.

Example 3

A compositions of the present invention is made as follows.

Ingredients Weight % cPVP-H₂O₂ powder 25 35% hydrogen peroxide 12.14 DCSilicone Fluid - 350 CST 15.96 (Dimethylsiloxane) DC 8-7016 Fluid(Silicone 30 Adhesive) sodium saccharin 0.3 Pluracare L-1220 1 Plastigel5 15 mint flavor 0.6 Total (%) 100

The composition is made by a process generally as described above inExample 1. The composition is subjected to accelerated aging conditions(105° F./120° F.) for several weeks, and remains stable with more than90% of the peroxide remaining.

The whitening efficacy of the composition is determined using aduplicate pair of flow cells designed to accommodate a total of eightbovine enamel blocks (four in each cell). The bovine enamel blocks areobtained freshly stained using an established staining protocol (IndianaUniversity, Indianapolis, Ind.). The initial L*, a* and b* values arematched as closely as possible prior to an experiment using achromometer (Minolta CR-321) based on initial L*, a* and b* values(CIELAB). These initial values are typically L*=25.00, a*=3.00, andb*=5.00 to L*=35.00, a*=5.00, and b*=7.00. The L, a, b values aremeasured four times at slightly differing locations on the surface ofthe bovine enamel blocks.

To simulate the saliva of the human mouth, an artificial saliva buffersolution maintained at 37° C. is prepared which contains the saltsusually present in saliva at levels typical to the levels found in humansaliva. The bovine enamel blocks are placed in the flow cells and thecompositions evenly applied using a brush, the amount of product appliedis determined using the weight difference of the container. Flow overthe teeth is 0.6 ml/min. for 30 min. Average initial and finalchromometer readings is used to calculate ΔE according toΔE=((L_(f)-L_(i))²+(b_(f)-b_(i))²+(a_(f)−a_(i))²)^(1/2). The results ofthe tests, set forth in the following table, show that the compositionhas a whitening effect.

ΔL Δb ΔE 12.7 ± 1.7 −5.7 ± 1.4 14 ± 2.1

1-29. (canceled)
 30. An oral care composition comprising: (a) a peroxidecomplex comprising a peroxide component and an N-vinyl heterocyclicpolymer; (b) a whitening agent; (c) an orally acceptable carrier;wherein the peroxide complex comprises a cross-linked polyvinylpyrrolidone-peroxide complex, wherein the whitening agent compriseshydrogen peroxide, and wherein said carrier comprises a block copolymerof ethylene oxide and propylene oxide.
 31. The composition of claim 30,further comprising tetrasodium pyrophosphate.
 32. The composition ofclaim 30, further comprising calcium pyrophosphate.
 33. The compositionof claim 32, further comprising tetrasodium pyrophosphate.
 34. Thecomposition of claim 30, further comprising polyethylene glycol.
 35. Thecomposition of claim 31, further comprising polyethylene glycol.
 36. Thecomposition of claim 32, further comprising polyethylene glycol.
 37. Thecomposition of claim 33, further comprising polyethylene glycol.
 38. Thecomposition of claim 30, wherein the peroxide complex is present at alevel of 0.5% to 40%.
 39. The composition of claim 30, wherein theperoxide complex is present at a level of 20% to 30%.
 40. Thecomposition of claim 30, wherein the peroxide complex comprises aperoxide component at a level of 1% to 25%.
 41. The composition of claim30, wherein the peroxide complex comprises a peroxide component at alevel of 5% to 18%.
 42. The composition of claim 30, wherein the molarratio of the peroxide component to the cross-linked polyvinylpyrrolidone is about 1:1.
 43. The composition of claim 34, wherein thepolyethylene glycol is selected from PEG-200, PEG-300, PEG-400, PEG-600and PEG-2000.
 41. The composition of claim 34, wherein the polyethyleneglycol comprises PEG-600.